A quiet revolution is underway in the world of hydropower. A suite of emerging technologies holds the promise of a benign form of power generation that, unlike today's big-dam hydro, does not ruin rivers, wipe out wildlife and destroy communities. While the global big-dam industry is desperately trying to put lipstick on a pig and rebrand conventional hydropower as "sustainable," wave, tidal and river free-flow hydro are fast developing into a viable and genuinely green hydro option.
The two green hydro sectors receiving the most attention are wave power and "hydrokinetic" turbines that capture energy from the flow of water in rivers, estuaries and ocean currents. Hydrokinetic, or "free-flow" turbines can even produce power from irrigation canals and water supply and disposal pipes.
Its hard to keep up with the rapidly developing sector. Just since the start of May the massive German utility E.ON launched into Scottish waters for advanced testing the Pelamis 2, a 750-kilowatt wave energy device comprised of three floating long metal cylinders; a UK company unveiled the final proof-of-concept trial of another sea-snake-type design, the Anaconda, which is made from a composite of fabric and natural rubber; and another British company unveiled the design for the next generation of its Oyster device, a floating hinged flap resembling a gargantuan bivalve.
The most recent issue of International Rivers' newsletter World Rivers Review has a cover story by me outlining the current status of non-dam hydro.
Brazilians have a joke that theirs is the country of the future ... and always will be. For years, wave and tidal power similarly seemed to be on the verge of a breakthrough into the big league of power sources, but for technical and cost reasons failed to meet the promise. Today, concerns over climate change and a sharply rising tide of political support for renewables, coupled with steady technological progress and investor interest, mean that the future has finally arrived for the new hydropower.